title: Increased incidence of gastrointestinal cancers among patients with pyogenic liver abscess: a population-based cohort study.
abstract: OBJECTIVE
  The relationship between pyogenic liver abscess (PLA) and gastrointestinal (GI) cancer was first reported more than 20 years ago, yet little is known about this connection. We evaluated this association in a population-based, retrospective, cohort study.
  
  
  METHODS
  Using Taiwan National Health Insurance claims data, we collected data on a cohort of 14,690 patients with PLA diagnosed from 2000 to 2007. A reference cohort of 58,760 persons without PLA (controls) was selected from the same database, frequency matched by age, sex, and index year. Both cohorts were followed up until the end of 2009, and incidences of GI cancer were calculated.
  
  
  RESULTS
  The incidence of GI cancer was 4.30-fold higher among patients with PLA compared with controls (10.8 vs 2.51/1000 person-years). Site-specific analysis showed that the highest incidence of colorectal cancer was among patients with PLA and diabetes mellitus, followed by patients with PLA without diabetes and controls with diabetes (9.58, 5.76, and 1.49/10,000 person-years, respectively). The PLA cohort also had a high risk of small intestine cancer (adjusted hazard ratio [aHR], 12.7; 95% confidence interval [CI], 5.79-27.7) and biliary tract cancer (aHR, 9.56; 95% CI, 6.68-13.7). Their risk of pancreatic cancer (aHR, 2.51; 95% CI, 1.68-3.76) was also significant. However, patients with PLA did not have an increased risk of gastric cancer compared with controls.
  
  
  CONCLUSIONS
  In a population-based study, we found that the incidence of GI cancer is increased more than 4-fold among patients with PLA compared with controls. PLA might therefore be an indicator of GI cancer. Patients with PLA had the highest incidence of colorectal cancer, followed by cancers of the biliary tract, pancreas, and small intestine.
authors.affiliation: School of Chinese Medicine, China Medical University, Taichung, Taiwan; Graduate Institute of Clinical Medical Science, China Medical University, Taichung, Taiwan; Division of Hepato-gastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Hsueh-Chou
authors.initials: HC
authors.lastname: Lai
authors.affiliation: Management Office for Health Data, China Medical University Hospital, Taichung, Taiwan; Department of Public Health, China Medical University, Taichung, Taiwan.
authors.forename: Che-Chen
authors.initials: CC
authors.lastname: Lin
authors.affiliation: Division of Hepato-gastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan; School of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Ken-Sheng
authors.initials: KS
authors.lastname: Cheng
authors.affiliation: Division of Hepato-gastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan; School of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Jung-Ta
authors.initials: JT
authors.lastname: Kao
authors.affiliation: Division of Hepato-gastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan; School of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Jen-Wei
authors.initials: JW
authors.lastname: Chou
authors.affiliation: Division of Hepato-gastroenterology, Department of Internal Medicine, China Medical University Hospital, Taichung, Taiwan; School of Medicine, China Medical University, Taichung, Taiwan.
authors.forename: Cheng-Yuan
authors.initials: CY
authors.lastname: Peng
authors.affiliation: School of Medicine, China Medical University, Taichung, Taiwan; Department of Family Medicine, China Medical University Hospital, Taichung, Taiwan.
authors.forename: Shih-Wei
authors.initials: SW
authors.lastname: Lai
authors.affiliation: Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan.
authors.forename: Pei-Chun
authors.initials: PC
authors.lastname: Chen
authors.affiliation: Department of Public Health, China Medical University, Taichung, Taiwan; Institute of Epidemiology and Preventive Medicine, College of Public Health, National Taiwan University, Taipei, Taiwan. Electronic address: tw.mohd@gmail.com.
authors.forename: Fung-Chang
authors.initials: FC
authors.lastname: Sung
mesh_terms: D000328:Adult; D001661:Biliary Tract Neoplasms / Q000453:epidemiology; D016022:Case-Control Studies; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology; D003920:Diabetes Mellitus / Q000453:epidemiology*; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000453:epidemiology*; D006801:Humans; D007710:Klebsiella Infections / Q000453:epidemiology*; D046290:Liver Abscess, Pyogenic / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D010190:Pancreatic Neoplasms / Q000453:epidemiology; D012189:Retrospective Studies; D012307:Risk Factors; D013274:Stomach Neoplasms / Q000453:epidemiology; D013624:Taiwan / Q000453:epidemiology
keywords: CI; Colon Cancer; DM; GI; HR; ICD-9-CM; Infection; International Classification of Diseases, Ninth Revision, Clinical Modification; PLA; Pancreas; Risk Factor; aHR; adjusted hazard ratio; confidence interval; diabetes mellitus; gastrointestinal; hazard ratio; pyogenic liver abscess